During a conference held in Geneva on May 6, World Health Organization experts warned on the increased risk of a human bird flu pandemic, as the bird flu virus gains more ground than ever.

“We can’t delude ourselves. The threat of a pandemic influenza has not diminished,” Keiji Fukuda, coordinator for the WHO’s Global Influenza Program, said, as quoted by the Associated Press.

At least 150 health experts met on Tuesday to discuss how to increase defense against a deadly global pandemic.

Scientists have long warned that the H5N1 strain of bird flu virus could mutate into a form that spreads easily among humans, leading to a pandemic that would kill millions. So far, most human cases have been linked to contact with infected birds.

The bird flu virus began ravaging Asian poultry stocks in late 2003. According to the WHO, there have been 382 human cases worldwide since 2003, 241 of them fatal. Indonesia is the hardest hit regions of all, with 108 of the deaths and is seen by health experts as a potential hotspot for a pandemic.

WHO says most countries have a plan to fight a pandemic but how prepared these countries really are varies. The organization aims to revise its 2005 guidance to its 193 member states by year-end.

“We are going to improve our guidance and give people and countries better tools to deal with. Pandemic preparedness is not just a health sector effort, it is something that requires the whole of society's perspective,” Fukuda said.

At least 16 drugmakers are working in developing vaccines to prevent bird flu infection in people.

“Some are very close to regulatory approval. These are the newer generation vaccines which use less antigen and contain adjuvant but still stimulate an immune response,” Fukuda said.

Fukuda said the WHO's global stockpile of the antiviral medication oseltamivir (Tamiflu) contains 5 million treatment courses, and the organization is developing a vaccine stockpile that will initially contain 150 million doses.